text:
Airplanes in static display at Whiteman AFB
After reading the post about B-2 sizing, I spend a couple of minutes on Google Maps looking at airplanes on the Whiteman AFB.
On runways, I think there are one B-2 Spirit, 3 T-38 Talon, and one AH-64 Apache.
On static display, I have spotted an F-111, one B-52 (north of the base), one A-10, one T-38, one B-47, and one B-29 at the south gate.
But there are also 3 more fighters at this location.

Center one seems to be an F-22 Raptor.
What are the two other ones? And is there any more static airplanes spread over this base?

That's not an F-22 -- the wings are the wrong shape, for one.

F-100, F-15, and F-4.  There is no F-22. The thing that looks like a brown nose cone on the F-100 appears to actually be the long, nose-mounted pitot boom, painted a light color, with its shadow visible just above it in the photo, all blurred together to give the impression of a much wider object.  It's clear from the shadow of the fuselage that the fuselage truncates abruptly in front, as per the air intake of an F-100.
All these three types were used by the US Air Force.
According to Wikipedia the F-100 on display at this base is a D model, number 55-3667.
Aerial Visuals has information about it, the neighboring aircraft, and other aircraft on display on the base.
This facebook page  describes these three aircraft being moved to their current location, with closer photos of the F-100.
This webpage of military aircraft on display in Missouri also has photos of these 3 aircraft before they were moved to Whiteman AFB (see the "St. Louis, Lambert Field" section), as well as other aircraft on display at Whiteman AFB.
These three types were all flown by the Missouri Air National Guard 131st Fighter Wing, now the 131st Bomb Wing- a unit currently based at Whiteman AFB.  Read more about it on this Wikipedia page.

The AeroVisuals website is confusing- in one place, based on the coordinates, sites "a", " b", and " c" appear to refer to the 3 planes on display side-by-side, but in another place it says site c is not accessable to the public but sites a and b are.  Looks like the website could use a little help!

Now I'm at my laptop and can see the photo a bit sharper than I could on my phone-- changed answer just a tiny bit to better explain the apparent "nosecone" of top plane.

"based on the coordinates, sites "a", " b", and " c" appear to refer to the 3 planes on display side-by-side" -- because they are each about one second apart in terms of latitude.

which is about 100 feet

Considering that it was not initially clear that the brown thing at the front of the top plane was not a nose cone, here are some of the observations that initially steered me away from F-11: large size.  Canopy far behind front of "nose cone".  Wing fairly tapered (small chord near tips) rather than closer to constant-chord.  Wingtips not obviously rounded.   Side intakes appeared small on first glance and entirely absent on closer look.   Just in case you were curious...  At one point F-101 even crossed my mind-- seemed a good fit for the relationship between the canopy and the more

At one point F-101 even crossed my mind-- seemed a good fit for the relationship between the canopy and the more forward portions including the apparent "nose cone"-- but of course the jet exhaust arrangement was all wrong.  Finally I realized there was no nose cone in front.

Last 2 links found by simply googling "F-100 Whiteman"

It's not an F-22.
From left to right:
Maybe F-11 (though I'd be surprised if there were F-11s with the "european" camo),
F-15,
F-4

Indeed for the F15, I found it in the meantime on the wiki page of the base: moved from Lambert-St. Louis International Airport.

Looking at 3-view on wikipedia I would say F-11 wings are closer to constant-chord-- wings of this plane are too narrow near tips for F-11, also F-11 wingtips are more rounded, and intakes should appear bigger.  Don't know what it is.  Also maybe too big for F-11.

Ok got it now--

Also F-11 wasn't used by USAF as far as I know!

Yeah, Navy jet gate guarding an Air Force base?... you'd sooner find a MiG...


text:
Airframe parachute on commercial airlines
My question, would a multi-deployment airframe parachute system be viable on a commercial airline? For example, Grumman & Cirrus already use this system.
As with the automobile industries, they were found to be culpable of many road deaths prior to implementation of seatbelts (refused by all the automakers at the time), so is it the airlines' responsibility for not making flight safe enough when the technology is there to implement?
You cannot buy a new car without it having airbags, why not airframe parachute on every new plane as a standard?

What is a space frame parachute? Is it for the whole plane, chunks of the plane, or passengers? (we have questions already asked about all three: all are not cost-effective and would not be useful in the vast majority of fatal crashes, and cost-benefit analysis still applies when dealing with miniscule risks to life or else we'd have banned cars long ago, but I'm not sure if this question is a duplicate of this, this, or this).

@cpast after researching about Grumman & Cirrus, I'd say what he meant was "airframe parachute".

@AndrewT. Ah, makes sense.

@AndrewT. bur neither of those are commercial, are they? did he meant "civilian"?

@Federico I think he's saying "these non-commercial planes have it, why not commercial planes?" Also, since the comment didn't post, possible duplicate of Why don't big commercial planes have full aircraft parachutes?.

@cpast it did not post because you already linked the question.

Cirrus builds very small planes that fly at a very low altitude and at very small speeds, hence the parachutes (CAPS) can be used.
General aviation aircraft are HUGE, BULKY and designed to fly at very high mach numbers. They are not designed to "withhold spin" as required by the CAPS.

Moreover, if this was possible, this would already be in action, because an Automobile accident is not much of a Headache for auto companies, but an Aviation disaster is for sure a PR nightmare for an Aviation Company.

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authors: سديم التميمي

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text:
Are there any widely applicable models for plausible aircraft auto-routing?
Aircraft travel in well defined airways, at different flight levels depending on direction and also have specific rates of ascend, descend and turn (e.g 2-min turn).
Are there any known models that take these spatial constraints into account and produce a plausible route between two points in space for a given aircraft?
My specific use case is straightforward: I have the current position of an aircraft and a number of alternative endpoints on that route. Instead of drawing straight lines between these alternatives, I would like to draw plausible routes taking into account as many real constraints as it is possible.
I haven't look into how this is implemented in computer games yet (e.g. flightgear) and I could write a simple enough auto-router taking into account the rate constraints. I would however like to know if there are any widely accepted or recommended existing auto-routing models.
Additional Information
In view of comments to this question I would like to clarify the following:

I am not looking for flight-planning algorithms or constrained
routing in the sense of optimal paths that are sometimes sought by
algorithms such as those used in this paper.
I am looking for routing algorithms whose output is the actual path
that if set on an autopilot will bring the aircraft through an
endpoint at a specific bearing, level and speed. Ideally, I am
looking for "names" in the same sense that the paper linked above
states "...some auto-routers for military aircraft do exist including
CLOAR, OPUS and JRAPS...".
As a secondary question, do ATC systems have some sort of
auto-routing as an aid to operators at busy areas? If yes, then
perhaps it would be worth checking if the algorithms are published
because I expect they would have to be standardised and validated.
As an example, consider an aircraft that is approaching an airport to
land. The aircraft is on a specific course, flight level and speed
and it is to be directed to enter the landing pattern at a specific
point. An approach would be to extend the entry point's bearing and
aircraft's bearing and fit a cycle that corresponds to the 2-min turn
to bring the course of the aircraft on the entry point bearing (i.e.
smooth the corner of the intersection). If such an intersection is
undefined (e.g. the bearings are parallel, or they intersect at a
really long distance) then a new leg needs to be added which a)
intersects with the current course of the aircraft b) intersects the
entry point bearing and c) satisfies other constraint (e.g. shortest
distance, no sharp angles, etc). If that is undefined on the side of
the entry point a new leg must be added, this leg should a) intersect the given leg at...and so on.
This approach will result to a path (not THE path) that respects specific
constraints...But obviously the question here is how realistic it
will be both for an aircraft to fly but also would a human operator
produce a path with similar qualities or reject it altogether? Hence,
the question...are there any auto-router algorithms out there
already?

Edit

If the general consensus veers more towards a situation where it is very hard to get acurate information on routing models for civilian aircraft, is there a set of minimal parameters that would have to be taken into account when designing a simplistic auto-router that would be more likely to generate plausible paths given two points in space? "Plausible" is defined as "similar to what a human ATC would have directed the airplane to do" or "a path that appears sensible to an average pilot". At the moment I would be considering the rates of ascend, descend and turn.

Intuitively, when I read your question, I think the answer should be somewhere in the region of dynamic programming algorithms. Perhaps that can help your search.

Thank you for the pointer, dynamic programming definitely has a place in the solutions to this problem but I am looking for established models (or algorithms) at a first instance. Not sure if ATC equipment has auto-routing functionality (?), that must have been standardised and validated so far.

Airlines do the routing, so you'd be looking for their models.

Thanks. Just to clarify that I am not interested in the broad flight plan. I am interested in what happens, for example, when an aircraft is about to land and it is rerouted to a holding pattern due to high traffic. So, given current aircraft, route and speed and endpoint data (entry bearing, entry level, entry velocity), solve for a plausible route.

I for one am certain that routing problems like this are actually NP hard and are undoubtedly very unpleasant multidimensional nonlinear optimisation problems. It might be interesting to consider a "2D ish" toy model as an illustration -- say, routing electrical traces on a printed circuit board, which, as Wikipedia lovingly says, is far from straightforward!

Note, that aircraft don't always travel well defined airways. Ad-hoc routing is possible. How common it is depends on operational constraints of ATC in given area.

Thank you all for your comments. In view of those, I have amended the question in the hope that it is now more accurate. I have actually written an auto-router for block diagrams based on an iterative approach and I would like to keep implementation details for later when I know what I am dealing with. At the moment I am looking for established models (if there are any) but feel that I lack the correct terminology to get any meaningful results from plain web searches.

I am looking for routing algorithms whose output is the actual path that if set on an autopilot will bring the aircraft through an endpoint at a specific bearing, level and speed

There are indeed models for moving between waypoints: I remember siting on the flightdeck of an A320 and noticing the airspeed increase as we descended towards the airport. I asked the pilot and he responded that this was in preparation for a turn coming up as to not loose airspeed. Not a huge differences perhaps but will make a difference over a year with a lot of aircraft.
Most airlines have company routes detailing which waypoints to use to a destination. To the best of my knowledge, these are fairly standard (you might have  few) and not too weather dependant, unless there is a big storm for instance. One exception to this are transatlantic tracks that are changed daily depending on weather. At least for most flights, possible variations are few and will be in busy airways. Changing airways is normally a larger deviation so it is just good to bare with it, and the weather is unlikely to be considerably better for just a slight detour.

As a secondary question, do ATC systems have some sort of auto-routing as an aid to operators at busy areas?

ATC have normally no real incentive to cut down routes, at least in cruise. They might help you skip some waypoints and get the aircraft down a little quicker if the airspace is calm during arrival. To also put things into perspective, I was on the flightdeck into a moderately large european airport where we were put first into a hold due to bad planning and then told to speed up after we left it to catch up again. Arlanda airport had something going on however with green approaches.

I am looking for routing algorithms whose output is the actual path that if set on an autopilot will bring the aircraft through an endpoint at a specific bearing, level and speed.

The issue here is that there is no incentive for aircraft manufacturers to release such algorithms to the public. If Airbus uses algorithm A, and Boeing algorithm B, each with a different inputs, you neither would want the other to make algorithm C that works with both inputs and being more efficient. The bottom line however is that everybody remains constrained by the infrastructure already in place that is pretty rigid.

Thank you for your response which to an extent it is useful and I guess, lined up to be accepted in the end, in the absence of a more accurate one. I have amended the question without any intention to be a pig about it but if there appears to be nothing relevant out there, I might as well put together something simplistic, yet plausible.

Note that most of the routing actually happens in a computer on dispatcher's desk. It does have auto-routing and it is really sophisticated, because it takes into account not just fuel burn, but also overfly charges and any restrictions that apply to the plane on the particular day—it's base ETOPS rating, but also any MEL items that have additional restrictions—and of course forecast winds aloft. The on-board system basically just recalculates the top-of-descent.

Both ForeFlight and DUATS provide airway auto-routing.
From the comments in your question, I suspect this is not what you want, but I'm offering it as an answer just in case.

Indeed not exactly what I am after but +1 for what appears to be routing web services from Lockheed Martin.

I'm with ForeFlight and wanted to let you know we have a commercial API that offers exactly this service. As @thunderstrike said, I'm afraid you'll find most services like this are commercial in nature as the formulas are proprietary and the potential cost savings can be very high.

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text:
Can I fly under a Military Operations Area (MOA)?
If a  a Military Operations Area (MOA) is designated from 10,000 to 18,000 feet, can I fly under the airspace without any permission?

You can fly IN an MOA without permission, so you can certainly fly under one.

@Dave-CFII -- that's true for VFR, but not necessarily for IFR.  And it's often ill-advised to fly in a MOA even VFR: students flying formation & acrobatics at speeds up to 500 kts don't really mix well with General Aviation aircraft at ~100 knots.  That all said, the floor is the floor and your point about flying under one is entirely correct.

Under IFR you really don't fly anywhere without a permission from ATC, unless you are handling an emergency.

Yes you can. The MOA floor, 10000ft in this case, is the lower limit of any restrictions a MOA imposes. Otherwise there would be no point in assigning a floor to MOA (or any other airspace for that matter)
See FAA AIM Section 4. Special Use Airspace

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text:
What classifies as an ultralight vehicle?
I am looking into the possibly of getting my pilots license and I noticed that it says you don't need a license for "ultralight vehicles".
What are ultralight vehicles?
I am located in the USA, and I am particularly interested in details for the states Utah and Washington.

Hi.  Welcome to Aviation.SE.  What country are you asking about?  The definition varies, as you can see here.

Just because you don't need one doesn't mean you shouldn't get one. Jumping into an ultralight without training is a good way to remove yourself from the gene pool.

A typical ultralight looks like this, although there are plenty of different designs:

Source: wikimedia.org
Ultralights in the US are defined and regulated by 14 CFR 103. The definition in 103.1 is:

For the purposes of this part, an ultralight vehicle is a vehicle
  that:
(a) Is used or intended to be used for manned operation in the air by
  a single occupant;
(b) Is used or intended to be used for recreation or sport purposes
  only;
(c) Does not have any U.S. or foreign airworthiness certificate; and
(d) If unpowered, weighs less than 155 pounds; or
(e) If powered:
(1) Weighs less than 254 pounds empty weight, excluding floats and
  safety devices which are intended for deployment in a potentially
  catastrophic situation;
(2) Has a fuel capacity not exceeding 5 U.S. gallons;
(3) Is not capable of more than 55 knots calibrated airspeed at full
  power in level flight; and
(4) Has a power-off stall speed which does not exceed 24 knots
  calibrated airspeed.

And 103.7(b) says:

(b) Notwithstanding any other section pertaining to airman
  certification, operators of ultralight vehicles are not required to
  meet any aeronautical knowledge, age, or experience requirements to
  operate those vehicles or to have airman or medical certificates.

But, just because you can fly an ultralight without any license or training doesn't mean it's a good idea! You should definitely look into local ultralight clubs to help get you started safely. For example, the EAA has a lot of members who fly (and sometimes build) ultralights and they have some useful information on getting started.


text:
ASTERIX category 240 fields placement in a UDP packet
I searched the placement of ASTERIX Category 240 radar video data fields in a UDP packet. But I cannot find any useful info. Is there a standard for this work?

I don't think the Aviation section of the Stack Exchange is the appropriate section to ask this question.

@SkipMiller I think it fits. Not possible for me to answer it from mobile phone now, but I am happy to take it later.

The Asterix structure is explained in detail on this document on the Eurocontrol site.
Wireshark.org has a page explaining the protocol as well.

Thank you @GdD. Will I be able to decide whether the received packets are in CAT 240 protocol? You mean that I can decode & analyze & seen all necessary fields of CAT 240 by using Wireshark? I have downloaded and opened the sample pcap given page you shared. In which ASTERIX category are these UDP packets encoded? Is there a method? I want to say "Yes, this UDP packets in the Wireshark are ASTERIX Category 240 or Cat ..etc"

Wireshark should be able to tell you if it's cat 240, that's just a field in a fixed length packet, so even if the wireshark decoder doesn't say exactly which category it is you could figure it out yourself using wireshark's built in tools.

Correct. I got it. For instance, shared Wireshark pcap sample are seen cat 048 and cat 034.

It has been some time since this question was asked, but I still decided to answer it. Usually, ASTERIX messages are sent in UDP packets, but there is no dedicated standard port for that kind of messages. Sometimes, you can find information that that port should be 8600, but nobody really uses it.
Therefore, when you open ASTERIX recording, you see just raw data like this.

You have to setup Wireshark to decode ASTERIX data. Since data is usually sent to some predefined ports, you tell Wireshark to decode that data as ASTERIX. Go to Analyze -> Decode As..., and setup the UDP ports, where ASTERIX data is like this:

After you configure Wireshark, you can see decoded ASTERIX data.

However, ASTERIX Category 240 is not supported in Wireshark yet. Please, send me some sample data of Category 240, and I can add it to Wireshark.

Please see an example capture from Wireshark here for ASTERIX Category 240.                           https://drive.google.com/file/d/1D0IbSXZxQPXhK8mcVdZiO1NH4PzCDTDV/view?usp=sharing

@Bernard Peter I am not maintaining the ASTERIX dissector in Wireshark directly any more. Right now a new version of dissector has been submitted to Wireshark, which generates the code from ASTERIX specifications. Therefore, the decoding is not coded directly into source code any more, but the ASTERIX spec has to be entered, and from there the new code will be generated. Take a look here https://zoranbosnjak.github.io/asterix-specs/index.html, hos specs are defined, and contact an email published on "SOURCE" subpage to get specs for CAT240.

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text:
Why is not every airplane equipped with 3 angle-of-attack sensors?
For critical systems, redundancy is built into the system. It is common knowledge among designers/architects to have three different inputs so in case one is faulty, input from the remaining two can be used to find (and shut off possibly) the faulty one (two against one).
Why is not every airplane equipped with 3 angle-of-attack sensors and triple modular voting when these devices are critical for the safety?

The million dollar question

Do you know any aircraft with 3 AoA sensors?

Not only A320, all airbus aircraft have 3 AoA sensors. A350 even has additional 4th AoA sensor.

Interesting. Would be nice to know how 3 to 4 AoA sensors are being read out. It could be 2 per pilot, and still no TMR. Related question: https://aviation.stackexchange.com/questions/60972/is-it-common-for-automated-control-systems-to-use-non-redundant-sensors?rq=1

From what I know, each 3 AoA sensors is connected to each of 3 ADIRUs. ADIRUs decide when to switch functionality internally based on input received by them. For A350, 4th AoA probe is connected directly to FCGS computer.

@ymb1 Isn't that the case only when two fail in such a way that they provide the same value? If two out of three were to randomly fail, it seems pretty likely that they would fail in such a way that they provide different values, if any at all. IIRC, 888T was a common-mode failure: water freezing, presumably at about the same time in each.

The statement that a faulty AoA sensor is the cause of either crash has not been confirmed by the investigators or regulators.

Both the Lion Air and Ethiopian Air crashes are still under investigation; as such, this question is off-topic.

@Sean The question isn't about the crashes (especially as edited) so I don't think this is off-topic.

The MQ9 Reaper had 3 AOA sensors. Also, the B2 bomber has 3, but it's crash in Guam is (I believe) due to all three giving bad AOA readings. Theory on redundancy is if the same mechanic is working on all three...

Do you really mean "every airplane"?  Because if you include GA the answer is obviously cost and necessity:  Cost is prohibitive and they aren't necessary.  I might suggest you edit this to narrow down the type aircraft where you think having 3 sensors would make sense.

Triple redundancy is necessary to detect a fault and exclude it. The system then continues to operate through the fault. Double redundancy is used to detect a fault but cannot exclude it, so the system stops operating. The important fact is that the faults they actually detect are identical.
Stall events are rare and are normally not expected in flight. There is no immediate hazard if handling augmentation or stall warnings are disabled. Therefore, there is no need for triple redundancy.
Simply put, if the system detects an AoA discrepancy, it can simply trip off and stay off until it is repaired on the ground.
If the double redundant system is ideally designed, then only a simultaneous fault will escape detection. Note too that if the same simultaneous fault occurs to two sensors in a triple redundant system, then it will also escape detection because it will outvote the correctly operating sensor. Therefore, both systems share the exact same failure mode.
Double and triple simultaneous faults can and do occur with common causes including environmental factors (AF 447), maintenance errors (XL 888), and birdstrikes (US 1549). It also allows faults in the voting logic (QF 72). Both recent AF and XL fatal accidents are signs of an overreliance of buying 3 of the same box and then calling it "safe".

"only a simultaneous fault will escape detection" Only if they fail in the same way. Suppose two sensors, one reading -1 and the other reading +1; you can know they are reporting different values, but without additional knowledge, you cannot know which one is correct. In the case of three sensors, if the value set is (+1, +1, -1) you can reasonably (see XL888T) conclude that the -1 is in error; however, if the value set is (+1, 0, -1) you cannot conclude which, if any, of the values are right or wrong.

Whether faults are truly independent is another matter.  Multiple AOA sensors are likely to have been made by the same factory (and probably around the same time), maintained by the same mechanics and are flying through the same air.  That radically increases the odds of common mode failures, which will defeat any redundancy system.

@aCVn While true, AoA sensors failing simultaneously will almost certainly fail in much the same way: the only way they can realistically fail is through blockage (eg ice or debris). Ice buildup, for example, is likely to impact similar sensors in a similar way (see: AF447)

Two AoA sensors are more reliable than three!
Let's have a look at probability calculation, and assume the fault probability of one sensor to be p = 0.1 % (per flight, or whatever you like to choose). The probability of the same sensor to work as expected is q = 1 − p = 99.9 %.
Two Sensors
The probability for

no fault: q2 ≈ 99.8 %
a discrepancy (1 fault): 2 p q ≈ 0.2 %
an undetected double fault: p2 = 10-6

Three Sensors
The probability for

no fault: q3 ≈ 99.7 %
1 recovered fault: 3 p q2 ≈ 0.3 %
undetected faults: 1 − q3 − 3 p q2 ≈ 3 · 10-6

Which solution is preferable?
Autonomous system
If we were talking about an autonomous system, like a drone or maybe a satellite, we would be looking at the ability of the system to take a decision on its own.
A decision cannot be taken with

2 sensors if a discrepancy or a double fault occurs. The probability for that is 0.2 %.
3 sensors if more than 1 fault occurs. The probability for that is 3 · 10-6.

3 · 10-6 is 667 times better than 0.2 %. The autonomous system is better off with three sensors and TMR voting.
Aircraft with pilots
The situation is different if the system is monitored by a pilot, who can intervene in the case of a discrepancy. A false positive alarm is acceptable. Undetected faults are not acceptable.
The likelihood for an undetected fault is 1 · 10-6 with 2 sensors, and 3 · 10-6 with 3 sensors. The 2 sensor system is 3 times more reliable under this premise!
In addition, a single fault is more obtrusive in the case of the 2 sensor configuration. A single fault with three sensors - if noticed at all - is more easily ignored instead of being eliminated.

Logic in answer seems little odd to me. Why probability of sensor working in 3 sensor setup is q^3 and not 1-p^3? Isn't it that all 3 need not to be working for getting AoA information, only 1 is sufficient to do the job?

@MadMax: q^3 is (by definition) the probability for all 3 sensors working = no fault. 1-p^3 is the probability for 0, 1, or 2 faults combined. In a TMR configuration, 2 sensors are required for a correct results. 1 is not sufficient.

Originally gave +1 but after few days thinking realised that this is actually wrong. The three sensor case does not work like that. The system does not aggregate the ok/fail state, if it has that data it will just ignore failed sensors. What it aggregates is the actual measurement. So the relevant statistic for undetected is actually the probability of two sensors failing the same way and giving the same false measurement.  Usually this also needs to happen at the same time as the system would generally ignore the sensor that it thinks is giving false data. (cont.)

It is actually that ability to distinguish between the failures that is the benefit of three source solutions. Without it it would be a two source solution with extra points of failure. Which is essentially what you describe in the answer.

Mind you the above assumes the logic is implemented correctly. You can implement either system absolutely wrong and between them Airbus and Boeing have done exactly that.

Dear @VilleNiemi, you are right that my answer does not reflect the situation in the B737M. Instead it covers one theoretical aspect. To describe the scenario, it is not sufficient to count the sensors, but it matters how they are evaluated. The subject question keeps changing and adapting to the incomplete knowledge we have about an ongoing accident investigation. This should be avoided. Do you have reliable information about the B737M design? I do not. I consider moving this answer to a different question (to be created).

Regardless of the number of sensors, the pilot must have enough experience to tell what is going and just fly the plane. Checklists may help, but there may not be time. After the first 737 MAX crash, there was an Airworthiness Directive and a Notice to Airmen setting forth the way to deal with stabilizer runaway, whatever the cause, including MCAS. The 2nd crash occurred after the pilots first followed those procedures but then reversed them.
MCAS has been fixed. Regulators have stated and certified that point.
Pilot training has not been fixed. That's what needs to happen next.

I think this does not answer the question. The question is not focus on the B737 MCAS but on the number of AoA sensor on every aircraft (not even restricted to airliner) and your answer does not address the number of AoA sensor.

@Manu H, he is making a broader point that the number of AoA sensors is irrelevant if the pilot doesn't have the training or experience to recognize and react correctly to a failure.  Because why stop at 3?  Why not 4 or 5?  Plenty of airplanes have no AoA sensor at all and they are flown safely every day.

I worked for Marconi in the 80s. The triple system was created in Rochester in the 1980s. The Triple-redundant was a design and marketing/safety philosophy for the new airbus which was the first fly-by-wire passenger aircraft - Marconi's engineers designed electro-mechanical flight controls for fighter jets, drones, airships, helicopters using the MIL-STD-1553 standard and the 1773 protocol. Every senior Marconi design engineer was trained in-house to fly his own light aircraft by the company - the company also had its own airport. I doubt any company in the world, including Boeing, could remotely match their internal expertise in flight controls at the time. If Marconi designed -in x3 AoA sensors they did this for a very good reason.


text:
Is it legal for a pilot to let passengers steer during take off and landing?
Our company plane can be flown by single pilot without the need of a copilot. Several times while flying in the company plane our pilot allowed one of our company owner's family members take off and land the plane while a number of employees were on board. Both in take off and landing the plane got violently out of control jerking back and forth to the point that everyone on board was in danger. Our pilot took back over control of the aircraft barely averting disaster. Several of us that have been on those terrifying rides have made it a point not to fly if he is going with.
Is it legal for our pilot to let him do this with us on board? In the USA

What country? If the US, do you know if the flights were part 91 or part 135?

I updated the tags to "regulations", could you please add the relevant country regulations (e.g. "faa-regulations" for US)?

@MartijnVissers While certainly related, that question doesn't specifically ask about take off and landing.

I agree it is a duplicate. Landing and taking off is part of flying.

That question seems to be focused on private pilot operations, this seems to not fall into that category.

Lnafziger's answer to that question covers the applicable regulations. If the flight is Part 91, it's legal. If Part 135, it's not.

While it may be technically legal, the owner's insurance company will probably have something to say about it in the event there is a claim.  The owner and pilot need to understand and assume that if there is an accident claim with significant loss, and an insurance company, or NTSB, investigation concluded a non-pilot was in control, depending on details buried deep in the insurance contract, the insurer may decline to pay and they'll be in a WAY bigger world of hurt compared to just getting busted over violating a regulation.

Even operating under part 91 I would argue the legality.  If you are manipulating the controls you are acting as PIC, and there are specific currency requirement for carrying passengers.  That these passengers are employees, and presumably compelled to be there, (vs friends just out for some sightseeing) and control of the aircraft was given to a non pilot during the most critical phases of flight makes these actions very troubling.  This is definitely something that should be brought up with the director of flight operations.

@MichaelHall "Acting as PIC" means they are legally responsible for the flight, regardless of who is actually flying. Under Part 91, there is no requirement that the pilot flying be licensed. Consider flight training where the instructor is PIC and the student is doing the flying, including takeoffs and landings.

@StephenS, you make a good point, but consider that the CFI is specifically qualified to allow unqualified personnel to operate the aircraft during all phases of flight, and normally does so without passengers.  I understand that the CFRs don't differentiate critical phases of flight from letting someone make shallow turns at altitude to get a feel for flying, but my point is that letting a non-pilot take off and land with company passengers on board shows extremely poor judgment.

Of course this is opinion, and must be balanced against the level of danger of a non-pilot passenger perceives.  For some people mild turbulence is extremely disconcerting...

@MichaelHall Poor judgment, yes. Illegal, no. Unless 91.13(a) comes into play, of course, but there is a huge gap between what non-pilots are comfortable with and what is actually unsafe.


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Are there planes that can fly without wings? How would a plane be able to fly without wings?
Are there any planes that can fly without wings? How do they produce lift? How do they control the attitude?

Welcome to aviation.SE! Can you give an example or picture of an airplane without wings so that we can see what you mean? And the [tour] might be useful if you're new to the site.

Do you mean aircraft in general? A plane (short for airplane) is defined as "a powered heavier-than-air aircraft with fixed wings from which it derives most of its lift" according to Merriam-Webster.

@pondlife, that's what the OP is asking!

There is a certain class of aircraft that are lifting bodies, which do not have wings but instead rely on airflow over a peculiarly-shaped fuselage to generate lift. However, this method is very inefficient and requires high airspeeds to make enough lift to support the plane. This means that the plane would have to carry an enormous engine to propel it, and its takeoff and landing speeds would be very high.
Several experimental lifting-body planes were built and flown as gliders ~50 years ago for research purposes, and a search on lifting body will furnish you with more information on them.

I was thinking bags of helium ...

An aircraft's fuselage can provide significant amounts of lift. An Israeli pilot famously landed an F-15 with one wing completely missing.


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Is being a pilot stressful or hard?
As a Canadian teenager hoping to become a commercial pilot, I'd like to know how hard it actually is to live the life of a pilot. I've heard from some people that the hours can be pretty gruesome, which is obviously a little off-putting. Are you able to maintain a relationship?Are the hours off-duty at home plentiful enough or few and far between? Is the pay worth it? Do you get vacation days and/or sick days like any other job? Any details on the life of a pilot and whether or not you'd suggest it would be much appreciated.

Scheduling varies wildly depending on the type of operation: commuter vs. mainline domestic vs. short-haul int'l vs. long-haul int'l, pax vs. cargo, scheduled vs. unscheduled vs. charter vs. fractional vs. corporate.  And that's not even counting miscellaneous ops (part 91, as well as vertical reference and external load helicopter flying)

Hi Devin, welcome to Aviation.StackExchange!  Your question is one that a lot of people have, but I feel that it's too broad for this site, and it's going to attract a lot of opinion-based answers rather than the kind of fact-based answers that we're looking for.  Can you narrow your question down any?

possible duplicate of Burdens of working as an airline pilot


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Have objective and verified tests been done of the effects of personal electronic devices on a commercial airliner's operation?
Have any governmental agencies done comprehensive tests on the effects of personal electronic devices used in the cabins (and cockpits) of commercial airliners?
With the ubiquitousness of cell phones, laptops, kindles, ipads, etc, it strikes me that everyone seems to just know that using a cell phone in the cabin of an airliner has no appreciable/measurable affect on the electronics of the aircraft.

you start the question being neutral, you end it assuming nobody did it.

@Frederico I deleted the biased paragraph. You were correct.

Take a cellphone with you in the cockpit and you will witness yourself that it interferes with radio communication. You can hear in your headgear each time when it negotiates its connection with a cell tower.

@PeterKämpf Years ago, as a contractor to the US Government, I was issued a BlackBerry. That thing wa notorious for interference. Every time it checked status with the networks, 'bzzt bzzt bzzzzzt'. I don't recall hearing that with more modern cell phones, however.

@CGCampbell: My observation is a few years old, so I guess we had the same experience. It seems that modern phones don't stray as much in lower bands.

I believe [skeptics.SE] also has at least one question on this topic

The 'bzzt bzzt bzzzzzt' sound you used to hear from blackberries and older cellphones were not interference with the "electronics" as I recall, but rather direct interference with the wires leading to the speakers (or headphones).  Nuanced distinction, but important in this particular case.  It also would happen if you put the blackberry near a spiderphone or something on a conference table.  Very annoying I recall. :)

Here is the Skeptic question by the way:  http://skeptics.stackexchange.com/questions/1118/are-personal-electronics-a-risk-to-commercial-aviation  A couple years old.

Yes, they have done a lot of testing, hence why they now finally realize that most electronics are of no harm, and you can use them.
The FAA announcement page has a link to a fact sheet of their report, as well as a link to the PDF of the report.
In addition to the FAA report, other agencies have weighed in (such as Boeing).  Basically, the rules were instituted in the 1960s, and remained virtually unchanged since then, so it was time to make a change.

This change does not apply to cell phones except in flight mode. That seems an important detail.


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How can pilots differentiate runways and taxiways during landing?
There have been many incidents where pilots landed or attempted to land the aircraft on a wrong surface (for example Continental 1883 and Air Canada 759). Are there any tips for pilots to avoid that? Especially during nights or low visibility scenarios.

You might find this interesting: https://www.skybrary.aero/index.php/Runway_Identification

Can you point out a particular accident that happened when a pilot landed on a taxiway? Usually these don't result in accidents, they are classified as "pilot deviations" or incidents. I don't know of any "accident" caused by landing on a taxiway... There have been accidents involving landing aircraft coming down on top of, or running into aircraft on the runway during low visibility...

Closely related

@VvV Please don't hesitate to roll back if you don't like my edit!

I think this website should provide interesting reading for you: https://www.skybrary.aero/index.php/Inappropriate_use_of_Runway_or_Taxiway . I will not create an answer here, because I don't have the time to spare to copy-paste what you can find there. In particular, look into the document under "Further Reading" (direct link: http://www.skybrary.aero/bookshelf/books/4058.pdf )

Simple flowchart. Are you a pilot? N--> Doesn't matter Y--> Are you Harrison Ford? N-->You're landing on a runway Y--> You might be landing on a taxyway.

During daytime and good visibility, it should be pretty obvious that runway markings are white and taxiway markings are yellow. Runways have the runway designator in big white numbers at the end and a dashed centerline, while taxiways have a narrow continuous yellow centerline.

During nighttime, you will notice that runway lights are white or yellowish while taxiway lights are green (center) end blue (edge). Additionally, many runways have approach lighting, which taxiways obviously do not.

During low visibility, you won't be trying to identify the runway visually, since you will be performing an instrument approach, which will usually take you all the way to the threshold. For non-precision approaches, where some visual maneuvering is required, the information above regarding markings and lights apply equally.
In addition, taxiways are generally narrower than runways. While many runways do have parallel taxiways that run for the full length of the runway, in many cases the taxiways will have a few bends or be at a slight angle, whereas the runway will be completely straight and wider.
You should always study aerodrome charts and familiarize yourself with the airport layout before attempting to land at an airport. When doing so, pay attention to the airport layout, and try to notice any areas where confusion is likely (such as long straight taxiways that run parallel to a runway). If you come prepared, and pay attention to the details mentioned above, you should be home safe.

Dusseldorf Tower: “Taxiway Alpha to Romeo to X-ray.  Why are you confused, have you ever flown to Dusseldorf?  British Airways pilot: “Twice, in 1944, but it was dark, and I didn’t land.”

ExpediteDescent has done an excellent job of describing how pilots distinguish runways and taxiways. In addition to what he has posted, I would like to add that it boils down to situational awareness and proper prior planning. Runways and taxiways are very well identifiable from there markings, lights, and signs. And, only specially equipped aircraft with pilots who have received special initial and recurrent training and certification are allowed to land on a runway that they can not visually identify the runway environment. Aviation safety is built on redundancy. So, identification is not left up to chance.
For instance:

The markings, signs, and lights for runways are distinctly different from those of taxiways.
Runways are named and listed according to their magnetic heading/ground track
During taxiing, pilots should check their magnetic compass and  Directional Gyro/Heading Indicator against the known headings of identified taxiways.
Pilots should always check their magnetic compass and Directional Gyro/Heading Indicator prior to takeoffs and landings to ensure they are lined up with the correct runway.
Different runways of the same airport will have different runway lead-in lights (MASLR, ALSF, etc). Which type of leads in lights used will be indicated in charts, diagrams, and chart supplements.
Runways will usually have visual vertical guidance equipment next to them. Which side of the runway the equipment is on will usually be indicated in charts, diagrams, and chart supplements.
Even during good visibility, pilots can use ILS or RNAV equipment to double check they are landing on the correct runway.
Plenty of panel mounted and handheld electronics have the option to show the extended centerline of a chosen runway. I personally use this feature to double check the runway alignment of the airport on each landing. Especially those at unfamiliar airfields. It is as simple as hitting OBS on the Garmin and dialing in the magnetic heading of the desired runway.
Plenty of panel mounted and handheld electronics have the option to show the aircraft’s GPS derived position relative to their ground location on the map.
Plenty of panel mounted and handheld electronics have the option to show the aircraft’s GPS derived position relative to their ground location on sectionals, charts, and airport taxi diagrams. Many call this geo-referencing. I believe Garmin has trademarked the name SafeTaxi for this feature.
The airport taxi diagrams and chart supplements list areas on the airport surface where there might be confusion or a preponderance of error of mistaking one airport surface for another. These are labeled and described as Hot Spots for the pilot to exercise increased diligence.

These various methods and their redundancies work. Case in point: My local airport decided to build a longer runway parallel to their existing runway. They designated the old runway as a second, main taxiway. The configuration is new runway on the East, old (main outbound) taxiway on the West, old runway/new (main inbound) taxiway in the center. All running North-South. They still maintain the old runway as if it were still an active runway. They just changed the markings, signs, and lights. They have even had an opportunity to use the old runway/new taxiway as an emergency landing surface when the new/actual runway was shut down due to a wheels up belly landing. Since the new and the old runways are identical except for their markings, signs and lights, and they both start right next to each other on the North end, it would be very easy to mistake one for another. Through situational awareness and the redundancies listed above, that does not happen.

"Runways are named Andrew listed according to their magnetic heading/ground track", but I've called my George! I will hold him and pet him and take off from him. Actually, that looks like your train of thought jumped track right in the middle. Want to revisit that and/or make a further explanation to the non-pilots in the room?

@FreeMan - Darn spellcheck. That should be “Runways are named and listed according to their magnetic heading/ground track”. Thanks. I did not catch that Apple had changed what I had typed.

I realized that was probably the problem. Right after I hit <enter> on my comment. I figured I'd leave it since I was pulled out a good dad joke so early in the morning. ;)


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Aerospike nose cones for supersonic jets?
Not to be confused with aerospike nozzles. This is about the big pin-like rod in front of ICBM nose cones.
This answer (from Space) about aerospike nose cones notes that one of the potential advantages of the aerospike nose cone is to considerably decrease noise from the supersonic boom. In this comment the author evokes projections for the Concorde, dropping noise from 110 dB to 60-70 dB, that is 15 to 30 times quieter.
Noise from the supersonic boom, as the story goes, is what ultimately killed the Concorde: most nations forbid overland flight because of it, limiting it to ocean flights. So there would be clearly benefits from this.
Have there been any supersonic planes using this design that flew? Are there projects to do so that are currently active? Otherwise, why not?

"Noise from the supersonic boom, as the story goes, is what ultimately killed the Concorde" It isn't the only thing that killed the Concorde though. The Concorde was an incredibly uncomfortable aircraft from the passenger perspective. Airbus wasn't making parts, the avionics were antiquated, ticket prices were extremely high, Airbus didn't make replacement parts anymore, and nobody wanted to fly it after AF4590. You could say though that noise "killed the future of the super-sonic airliner"...

@RonBeyer True. What I meant is, it is often said to be (one of) the fundamental cause(s): had it not be barred from flying overland, there would have been many more orders, at least dozens. This would have made it more profitable and easier to maintain and keep pieces for it. Peak oil would have still hurt it, but maybe it would have been big enough to still stick around, instead of wasting away on a few, dying lines. it would have still have stopped flying at some point, but with the market open, others would have followed - so "killed the future of the super-sonic airliner" is indeed better

Noise, fuel consumption, the land overflight ban, and a fatal accident were four different nails in the coffin.

@RonBeyer Concorde was always sold out, except understandably for a few days after AF4590, until the very last flight; that means prices were too low.  The main economic problem was AF/BA only put a few of them in service due to perceived route viability; once a flight attendant discovered it was possible to charter them, though, the fleet was booked solid flying all over the world, and public flights actually became a side business.  They could still be flying today as charters if parts were still available.

Actually project bongo and bongo 2, were the issue. The brilliant military of the '60s decided they needed to fly low altitude supersonic flight over a midwest city several times per day for months on end, just to see what would happen because they thought sonic booms maybe useful as a weapon. This operation was the primary reason for banning supersonic flight over land. Though they really just irritated people and broke a couple windows they did collect some usable data on shock wave magnitude and dissipation.

The blunt nose design is used on modern rockets because it pushes the shock wave out passed the stabilizer fins, controlling drag and heat buildup. Heat is a notable problem starting about mach 2, this is why the SR-71 needed titanium instead if aluminum.

There are no historical aircraft with an aerospike nose, at least, none that I remember, and none that I could find after 30 mins of research. I'm not sure if there are any planned projects using it, but I doubt there are, given the purpose of aerospike noses - aerospike noses really only have one main purpose - to streamline a blunt body. This is commonly used in missiles and such (especially in SLBMs), where height/length is a constraint - a slender, sharp nose is very long, so to save height, those missiles are fitted with an aerospike that telescopes out. The flat plate at the end of the aerospace forms a detached bow shock, which makes the airflow "see" the blunt body as having a different, more streamlined shape, reducing drag. Here's a visual of that happening:

Image source - https://iopscience.iop.org/article/10.1088/1742-6596/1276/1/012031/pdf
However, the bow shock generated by a drag reducing aerospike causes more drag and a heating than the oblique shock generated by a slender nose of the same length. For SLBMs, a long, sharp nose is obviously out of question (well, you could have a telescoping sharp nose, but that would be heavy), but for aircraft, length really isn't a concern, you can make the nose as long as needed. Therefore, it doesn't really makes sense for an aircraft to have an aerospike nose.


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Why does the Blue Angels C-130 ‘Fat Albert’ have loadmasters?
In the Blue Angels FAQ it states that Fat Albert is made up of 7 crew, two of them being loadmasters. Why would you need loadmasters for a demonstration aircraft?

Semi-related, the current airframe is ex-RAF.      https://en.wikipedia.org/wiki/Blue_Angels  "The Fat Albert (BUNO 164763) was retired from service in May 2019 with 30,000 flight hours. The Blue Angels replaced it with an Ex-RAF C-130J (BUNO 170000).[84]"

Fat Albert’s primary purpose is actually transporting spare parts, tools, and maintenance personnel from show to show. Performing demonstrations is more of a byproduct of being part of the team.
Most crew-served aircraft like the C-130 fly with a standard number of personnel in each crew position, but that can change depending on the mission.  For example, a local area, post-maintenance check flight may fly with a minimum crew of two pilots, a flight engineer, and a first mechanic to assist with any items in the back-end such as opening hatches to ventilate smoke and fumes, manually cranking down landing gear in the event of a hydraulic failure, etc. (which loadmasters are also trained to do).
A normal crew for most missions contains at least one loadmaster, but depending on the amount of cargo and available personnel, it is fairly common to have two assigned.  Lengthy training missions may be augmented with additional pilots and navigators.
For the logistical support missions Fat Albert is tasked with, there definitely needs to be a loadmaster in the crew.  Fat Albert has two, not because it is necessary to have two on each flight, but because it is a small team on a tight schedule so there needs to be some redundancy in case one is injured or falls ill.
FYI, in addition to normal flight duties, on a demonstration flight that included a JATO shot, it is the loadmasters in the back who pull the jettison T-handles to dump the spent rocket bottles following the intercom command of the pilot.

As an aside, the mission/  role of day is largely irrelevant. C-130s are designed to be flown with an Air Loadmaster even if empty as many drills and systems are inaccessible to the pilots and require someone to be able to move around the aircraft.

@Arkhem, Good point, but I don’t agree the mission is largely irrelevant.  I have beefed up my answer as a result of your feedback though, so thanks.  And please let me know if you think it can be improved further.

No JATO on the current Blue Angels C130, it's a J model. I'd also expect the crew size to be smaller given the J doesn't require an Air Engineer or a Navigator.

@YanHolland, maybe it’s my age showing but JATO was part of the demo for a long time so I thought I’d mention it.  I changed it to past tense though…

You mentioned "dump the spent [JATO] rocket bottles".  Did they dump them to the ground?  BTW, they apparently stopped doing the JATO demonstration because they used up the last of the compatible rockets.

@RockPaperLz-MaskitorCasket, yes, we would fly out to an aerial target area and drop them from around 500-1000' AGL.

Thanks. That's interesting. Why did you elect to drop them instead of keeping them attached? Was it the added weight, or a different reason?

@RockPaperLz-MaskitorCasket, I really don't have any idea.  Maybe the mounts weren't designed for the stress of a possible hard landing?  Probably just because we could...  Maybe our transport pilots were all frustrated ground attack guys and just wanted to see how close they could get to hitting a target?


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Why should an overheated wheel be approached from the front/back and not in line with the axle?
According to the CAAIP
(Civil Aircraft Airworthiness Information and Procedures):/

10.4 Tests have shown that the safest extinguishant to use is a dry chemical agent and this
must be used whenever possible. It should be applied by an operator standing in line
with the tyre’s rolling path and at a safe distance; an overheated wheel should never
be approached in line with the axle.

But it doesn't state why it should be so.  Can you explain this?

Highly related

I'll link to this related Question/Answer. The diagram it quotes for "wheel/brake overheat hazard areas" makes a slightly different suggestion: you're apparently supposed to approach from from an oblique angle to the direct front/back, as directly front/back is the path for tire debris.

Besides staying clear of the fuse plug in the rim, it's partly because the sidewall of the tire is the weakest part of the carcass, so that a rupture from overpressure from overheating means most of the force goes sideways when the tire is stationary. The key word is "stationary".
When the tire is spinning, centrifugal forces mean the tread lets go from the sidewall all the way around, and the bits all go perpendicular to the axle, but when sitting still, it mostly goes sideways.
A secondary factor is the rims themselves. Aircraft wheels are built in halves and bolted together. They have to be made that way to ensure that there is enough overlap of the edge of the rim over the bead to prevent the tire from being forced off the rim by side loads.
You don't mount the tire the way a car tire is, by stretching the bead over the rim using a bar or in a machine.  You place each half of the rim into the tire from each side and bolt it together.
If you disassemble an aircraft tire by unbolting the wheel halves and forget to release the pressure in the tire, you get a nice surprise when you remove the last fastener (this happens with forgetful mechanics removing light aircraft tires from time to time).
Anyway, this means that if the wheel itself fails and breaks into pieces, the large chunks of metal will go sideways, mostly.
Bottom line is with a stationary tire, the heavy structure of the belted tread acts like a containment structure to protect you, so you take advantage of that.

Light truck rims (in the 3/4 to 1 1/2 ton range, maybe heavier but I was never around those) had split rims long ago -- and as late as the 1970s.  I knew someone who worked in a tire shop, and said split rims were the most dangerous to work on.

Yeah on those I believe the flange was bolted on instead of having the entire wheel in two halves, but dangerous nonetheless.  I mount my own car tires (because I'm nuts) using one of those harbor freight tire stands that you bolt to the floor.  The trick is to use LOTS of bead lubricant, and they go on easy peasy.  When I change a tire on my plane, I check the pressure's out prolly 3 times before I start unbolting it.

@JohnK multipart rims are still a thing in the automotive aftermarket today; for street cars I think it's mostly about simplifying logistics by being able to mix and match parts to offer more configurations with less inventory needed.

In fact go to any truck stop and you’re likely to see a tire cage—a cage enclosure that is placed around a semi truck’s tires when a rim set is first inflated.  Split-rim failures can easily be fatal and cause a lot of injuries every year.  A typical semi or bus rim failure can generate 60-80,000 pound-feet of kinetic energy.  I’m guessing an over-heated high pressure nitrogen 747 tire heated by a brake overheat could generate pressures more near a million pound feet were it not for fuse plugs.  There’s zero chance of survival and in fact zero chance you’d stay in one piece.

Those aircraft mechanics who forget to release the pressure ... do they live to tell the tale? Like, how bad are the results?

Depends on the size of the wheel. A 4 lb rim half popping into your face will hurt for sure, maybe break your wrist or something.  A larger one would get nasty. 25 psi pushing out on the surface area of the side wall adds up to a few thousand lbs. You have to be pretty careless because it should be pretty obvious the tire is pressurized as you back off the bolts and the halves start to spread.  I don't know how often it happens; fairly rare I'm sure.

Aircraft wheels have fusible plugs that blow out when high temperatures are reached. I am just guessing, but it stands to reason that it’s safer to approach an overheated tire from the front or rear in case the wheel plugs blow out.
The International Fire Service Training Association says to approach an overheated tire at a 45 degree angle.

Here is a video that shows these plugs blowing out:
B777 brake test

The weakest part of tire's structure is the sidewall, unless the wheel has been locked and the tire tread is severely worn out. If a tire is blown simply due to overheating, it most likely will eject shrapnel to its sides.
It is also possible that shock cooling of the wheel by extinguishing agent will cause it to shatter, again sending shrapnel mostly in the direction of the wheel axle. The cooling effect will largely depend on the type of extinguishing agent.

To add more detail to another, too-short answer, the primary hazard when using an extinguisher to cool an overheated wheel is blowout of the tire.  If this should occur, the relatively heavy tread and belts will tend to limit the velocity of tire fragments thrown in the rolling direction, as well as largely directing the pressure wave parallel to the axle.
For reference, I've seen a car tire, at a mere 2.3 bar during installation, blow out and break shirt buttons on someone standing a couple meters from the tire.  Many aircraft tires, especially those on relatively heavy airplanes, run at significantly higher pressures than a couple bar -- some heavy military tires well above 15 bar.  One of these tires can produce a very injurious pressure wave if it bursts, independent of any fragments.

The tire on a B52's were pressurized to 265 PSI, over 18 BAR. I did not work on F106's so I am not sure what their tire pressure was, but we had two airmen killed at Griffiss AFB back in 1986 when a F106 tire exploded during maintenance. You were suppose to depressurize the tire and pull the valve core when the tire was removed from the aircraft. Check the core was out when the tire was brought to the shop, and check again it was removed before working on the tire. All three times this was not done and men died because of it.

And there was an earlier case, also at Griffiss. 2 guys inflating a B-52 tire. Did not have all the bolts in and tight. Eventually, it let go. One of the bullets...er...bolts went through the shop door, across the adjoining office, and embedded itself into the far wall. No one died, luckily.


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What is the largest (size) solid object ever dropped from an airplane to impact the ground in freefall?
What is the record for the largest single solid item that has ever been dropped from an airplane at free fall to the ground?

Here, "free fall" means falling vertically, or nearly vertically falling allowing some leeway for expected horizontal movement such as the ground speed of the plane doing the drop, winds, or unintended Magnus effect among other things, and allows for normal atmospheric air resistance.
The object being dropped should be payload, not part of the vehicle doing the dropping.
The object should not be designed with the intent to generate lift. For example, the above mentioned Magnus effect would disqualify if a machine was purposely built to spin with the intention of generating lift. This includes things with wings, parachutes, landing thrusters, etc.
The object must have hit the ground in an uncontrolled descent in the past. In other words, satellites in free-fall orbit around the Earth do not count unless they fell to the ground and then got re-launched into orbit again (unlikely).
Objects that burn up in the atmosphere do not reach the ground as a single solid object, so they do not count unless any possibly remaining fragment that may reach the ground is still the biggest object to be dropped and reach the ground in its destroyed state (unlikely).
The item does not have to have been intentionally dropped. For example, if it were dropped with a parachute, but the parachute failed to deploy, that counts.
Bombs easily count as long as they don't have a parachute, thrusters, wings or any other design factor that is intended to generate lift.
Last, but not least, "largest" means greatest volume, not heaviest.

Comments are not for extended discussion; this conversation has been moved to chat.

I'm not completely sure I understand point 4, but I suggest rewording it to something like: "The object must have already hit the ground at some point before today. In other words, satellites which are currently, today, in free-fall orbit around the Earth do not count." Or, alternatively, simply "The object must not have been in orbit at any time."

Given the "aircraft" limitation, I would think some of the "massive ordnance" bombs would be about as close as it comes.  Several of these exceeded 10 tons.  Without that limitation the obvious winner is Theia, in "the big splash" that formed the moon.

Could you specify whether the shuttle being dropped from the 747 carrying it counts, and how you judicate on the shuttle 'dropping' it's main tank? Both are pretty much the end of the discussion if applicable.

A good candidate here is the US T-12 cloudmaker (https://en.wikipedia.org/wiki/T-12_Cloudmaker) at 43,600 lbs.

All bombs dropped from an aircraft glide. They do not fall straight down and hit the spot directly below the point where they were released.

That a bomb's trajectory, when dropped from a vehicle with a horizontal velocity, is not simply vertical has nothing to do with flying or gliding. It would demonstrate this behavior in a vacuum. It's just Newton's 1st Law in action.

@Dancrumb In fact, the effect would be even more pronounced in a vacuum, as there would be no drag to reduce its horizontal velocity in that case. However, dropping it from an airplane could prove quite problematic in a vacuum, as the airplane itself would have no lift (and, unless rocket-powered, no thrust) and would also follow a roughly ballistic trajectory toward the ground.

@dancrumb This study begs to differ with your conclusions. https://www.academia.edu/4005202/EVALUATION_OF_AERODYNAMIC_DERIVATIVES_OF_Mk82_BOMB_FROM_WIND_TUNNEL_TESTING_AND_SEMI-EMPIRICAL_METHODS

@reirab I specifically did not mention an airplane. The initial horizontal velocity of the bomb at the point of release is the primary reason it does not land directly below the point where it is released.
Aerodynamical effects will certainly have an effect on the specific spot that it lands, but these are a perturbation on the ballistic trajectory of the bomb due to gravity and the bomb's initial velocity.

@JuanJimenez if the study begs to differ with Newton's Laws of Motion then I don't care to take the time to read it. If, on the other hand, you're obliquely making the point that more than gravity affects the path of a falling bomb, then I would gladly concede that point, while re-stating that aerodynamic force are not a necessary factor to explain why a bomb does not directly below its point of release.

@JuanJimenez Nothing dropped from a moving aircraft falls straight down, so I'm not sure what point you're trying to make.

@DavidRicherby the one you just made  too. Thanks.

@JuanJimenez I get what you're trying to say, but in order for an object to impact directly below the point it was released it has to either a). Be released from a stationary point (no initial horizontal velocity) or b). Be able to maneuver itself/propel itself back to where it was released (as its momentum will carry it forwards).  Gliding is not the main cause for object to land in a different location than over where they were dropped, though the aerodynamics may change how far that distance is.

No, gliding is not the main reason, but it does contribute.

What about an airplane doing a loop and dropping it on the way down side of the loop?

I can't think of anything dropped from an aircraft larger than the US Space Shuttle when it was dropped from a specially modified 747 during the testing phases of development.

Comments are not for extended discussion; this conversation has been moved to chat.

If you consider the space shuttle an aircraft its self, the external tank was dropped after it was depleted and broke up on impact to the Indian ocean. The heavy early version weight 58,000 LBS empty and 1.68 Million LBS fully loaded. While not heavier than the shuttle it was volumetrically larger.

If we're counting the Space Shuttle orbiter, then I'd say it's probably that's probably the winner at around 150,000 pounds. As Juan's answer describes, it was dropped from the Shuttle Carrier Aircraft for glide testing before the first shuttle launches. The orbiter 'glides' about as well as the average brick, so this seems like it should count.
Other possible contenders I can think of:

Pegasus XL, an air-launched rocket. It is dropped from an aircraft, after which point its rocket motor ignites to launch a satellite into orbit. Approximately 51,000 pounds.
The Minuteman 1b inter-continental ballistic missile. While normally launched from the ground, a test was conducted on 24 October 1974 in which one was dropped and launched from the cargo bay of a C-5 Galaxy. According to the USAF, the dropped missile stack weighed 86,000 pounds.
The absurdly-large Russian fusion bomb RDS-220, better known in the West as "Tsar Bomba," coming in around 60,000 pounds.

It's also worth noting that all of these may be soon blown out of the water if Stratolaunch Systems gets their way. The Stratolaunch Carrier Aircraft is capable of dropping 550,000 pounds of rocket stack payload. The first test flight of the carrier aircraft has been completed, but it hasn't dropped a payload yet.

Good answer! I didn't know the Space Shuttle's approach glide ratio is 4.5:1, which is only slightly higher than the model concrete glider featured in MythBusters, at 4:1. And the empty weight of the Space Shuttle is only about 165,000 pounds, so a Stratolaunch mission could easily surpass that by a factor of about three.

Unfortunately I wouldn't put much faith in Stratolaunch.  They appear to be in much worse financial straits since Paul Allen died; and have cancelled development of an in house rocket in  lieu of only carrying Pegasus XL.  That rocket is extremely expensive for its performance level, so finding any customers is going to be a challenge.

@DanNeely Yeah, that's why I put the "if" in there. Even before Allen died, it seems like they've been having a lot of trouble finding the right rocket to launch from it.

Did the Tsar Bomba actually hit ground or was it detonated above?

@Polygnome It was an air burst, but most of it eventually hit the ground. :)

Not dropped from an aircraft, and was part of the vehicle but Saturn V’s first stage was jettisoned at the weight of more than 360000 lbs or 160000 kgs. On Apollo 11 the mass of the first stage was 363425 lbs when jettisoned. After that, it fell freely to the ocean.
Source: http://apollo11nasa.blogspot.com/2012/07/saturn-v-inert-weight-or-dry-weight-or_22.html?m=1

Hmm, that's pretty heavy.  May warrant it's own question of what is the heaviest man-made object to fall from space to the ground.

@RyanMortensen that honour would probably fall to Mir or maybe Skylab.

And S-1C stage did not fall from space. It was jettisoned at around 61 km, which is high for atmospheric flight but still well below Kármán line (100km). Also, the stack was travelling almost upwards at the time so it went on ballistic trajectory.

The MOAB  prototype was 30 feet long and 40 inches in diameter and hard landed. It seems to qualify, but it is a GBU with gridfins, so not totally a dumb bomb. It has almost the same envelope volume as the T12. You'd need an accurate scan of the two to figure out which had the greater volume.

I also seem to recall that large seaplanes were developed to carry boats out to bombed naval vessels. These weren't little rafts, these were plank on frame, wooden, ocean capable lifeboats with diesel engines that could be airdropped.
It also sounds like failed air drops could qualify - extraction chute functions normally, Main shoots or pallets fail completely. That has certainly happened a few time.
Several of the D-Day invasion towed gliders suffered catastrophic structural failures while being towed, and became qualifying items as they were jettisoned.

Since you have edited the question to require both "free-fall" and "second use in this fashion" (implying intentional dropping ), the answer is "none".  Things aren't dropped out of airplanes on purpose twice.

Parachutes are dropped out of airplanes multiple times on purpose (in most cases attached to a human).

There is no requirement for second use, only that the object has impacted the ground at a point in time prior to your answer.  Re-dropping is an optional possibility.

@RyanMortensen, maxim 11: Everything is air-droppable at least once.

@RyanMortensen sorry I did not understand "4. The object must have hit the ground in an uncontrolled descent in the past. In other words, satellites in free-fall orbit around the Earth do not count unless they fell to the ground and then got re-launched into orbit again (unlikely)".   I interpreted this as mandatory reuse.  What does this condition mean actually?

@Harper The condition is intended to exclude objects that have not yet completed their fall to make an impact with the ground such as items in freefall orbit around the Earth that are intended to perpetually remain in orbit.  *Some people were seemingly going out of their way to be kind of silly about supposed points of ambiguity, so I was pressured into adding this.


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Write my own autopilot software
For a hobbyist looking to write an autopilot program for a mode lUAV/drone, what are the aviation related considerations that would be involved in its design?  How could things like the ADC (air data computer), or pitot static system, be utilized to control bank angles and decent rates?  Are there any specific rules of thumb that would assist the autopilot in making smooth corrections?  For example, how should I calculate the max VSI in a climb or when approaching a level-off altitude, and is there a rule of thumb for bank angle in a turn?
Your answers will guide me in asking an educated question at the Programmers StackExchange and get programming specific advice on how to proceed.

This question appears to be primarily about programming, not aviation. It would be better suited on Stack Overflow.

@DannyBeckett it would get closed as too broad on Programming, and off topic on Stack Overflow.

Unfortunately just because it's too broad for Stack Overflow doesn't mean it works well here, for many of the same reasons. The question is currently too broad because there are a lot of unaddressed assumptions, the biggest one being "How complex do you want the autopilot to be?" (a simple wing-leveler / altitude-hold? A GPS-interfaced autopilot that knows about airspace and will keep you from flying somewhere you shouldn't?) -- There are RTCA standards but buying those might be overkill, you won't know until you refine your mission scope.

I vote to reopen the question, just because its broad doesn't mean that there isn't a general answer.  He's looking for a general consensus, not public static void main(String args) {}.  He can then take his more refined question back to Stack Overflow once he's on the right track.

Personally, I would characterize the task as requiring three areas of expertise. First you're looking at the usual programming skills required for any real-time process control application, which means writing efficient interrupt-driven code. Second, a good applied mathematics capability will be most helpful in designing the algorithms that you're going to code. Third, a thorough understanding of how an airplane is controlled will be required. I am unaware of any single book that would supply all the necessary information. I doubt there would be much of a market for such a text.

I like the question in general, and would like to see it better scoped.

@Terry, For a very simple AP, I think you'd actually be writing event-driven code.  Rasberry Pi would probably work brilliantly in this case.  Depending on how many people are working on this project, one wouldn't need hardly any understanding of how an aircraft flies to write an API that someone could implement.  In reality, at its most basic, all it should do is process information taken from the ADC and call functions like moveStab(+/-x).  Once implemented it would just require a bit of tweaking to prevent oscillations and for stability.  I doubt it would have to be FAA compliant.

@SHAF Stack Overflow would not be the place for such a question. Stack Overflow deals with actual implementation problems, Programmers deals with whiteboard problems.

@raptortech97, Sure, edited as required.

The edited version of the question is still, essentially, "How does autopilot software work". That's still far too broad.

This is an interesting question.  I wonder if things like an ADC with pitot/static system would even be used on a small drone/UAV.  Those are pretty big and heavy components.  I am pretty sure most hobbyist level aircraft would want to use something based on MEMS sensors which are readily available.  Something small and light like these, http://www.o-navi.com/.  Here is a pre-packaged autopilot. http://www.feiyu-tech.com/product-en.php?id=26

I would look at industrial control systems - like PID controllers as a guiding method. PID control is a heavily simplified version of what's at the core of a tomahawk missile.


text:
Do passengers notice if the aircraft is struck by lightning?
I recently saw a video from Valk Aviation
(actual scene)
of a KLM B777-300 struck by lightning on departure. It happened a few days ago.

I know this looks more frightening than it really is and the aircraft usually isn't harmed. There are numerous posts here covering this.
But I wonder what a passenger would notice when the aircraft gets hit? Is there some kind of BANG or something? Do the lights flicker, for example?
Terrys answer implies you cannot tell for sure so I guess you won't notice at all. Is that true?

"Is there some kind of BANG", yes thunder is the sound of air suddenly heated (and destroyed) by lightning. So it is maximum when the lightning is close to you. But close doesn't mean touching the aircraft, you can't tell the difference. However there is no need for touching the aircraft to have effects... so... it doesn't really matters. Sometimes the plasma created ("ball lightning") can travel in the cabin. This is a rare and strange event, but something you would remember ;-)

In my experience: Yes, the passengers notice, at least for some lightning strikes.
I was flying from San Francisco to Chicago, this was sometime in the 90s. There was a big snowstorm coming in to Chicago, and all you could see out the windows was snow illuminated by the landing lights. There was the usual murmur of conversations going on in the cabin, and all of a sudden there was an almighty BANG and the cabin went completely silent - everybody had stopped talking and was probably holding their breath. Several seconds later (seemed like a long time) the captain came on the PA and said

Nothing to worry about folks, we were just hit by lightning. We will be on the ground in Chicago shortly.

I am 100% certain that every single passenger on that flight "noticed".

Yes, lightning is extremely loud, and it makes a snap like a gun shot. The sound is so loud, it can damage a person's hearing. Also, if the window shade is open there will be a bright flash.


text:
Can someone tell me what kind of airplane this is?
It says Capt Nungesser on the tail. I’ve researched him but can’t find out what type of plane this is. French?

The aircraft with the inscription on the rudder "Capt Nungesser" is the French aircraft "Potez VIII" 1922 model type, the second version, equipped with a 70 hp. Anzani engine.
http://www.airwar.ru/enc/law1/potez8.html
Here is one picture from that site:

Great find! +1.

This is the correct answer and should supersede mine.

Apparently Nungesser brought three planes to the US for his barnstorming flying circus: the Potez, a Nieuport 18 and a Hanriot HD1. Remarkably the Hanriot has survived and is on display in California. https://earlyaviators.com/enunges3.htm

Fairly certain it's a Breguet Br. 14
Do you have any other pictures, or a higher quality one?

The tail is a lot different between the one you suggest and the picture the OP provided.

Not only the tail - the upper wing has distinct dihedral which is missing on the Breguet.

In the photo you linked to, the leading edge of the lower wing is nearly at the level of the bystander's shoulders.  Compare to the photo in the question...


text:
How reliable is the Airbus FAC calculated gross-weight?
I've noticed some variation between loadsheet weights and FAC (Flight Augmentation Computer) calculated weight. That's of course normal, since loadsheet is calculated with standard weights and FAC calculates the weight from alpha and speed (at least as far as I know).
Question: Does anyone have any information about the correctness and reliability of the FAC calculated gross-weight?
I'm also interested in how exactly, and with what parameters, the FAC calculates it.

Just as a little historical info, back in the pre-FAC days of the 1990s on 747-100&200 aircraft, after takeoff if we thought we were heavier than the load sheet showed, we could come up with our actual gross weight by working backwards through the tables for fuel flow, temp, mach number and altitude. This was on 747 freighters, and in third world countries they would routinely overload us. Even Japan Airlines would do it on contract freight flights by using 2.2 lbs per kilogram rather than the true value.

I just recall seeing somewhere that a warning message appears when the difference is over 4t so clearly that is when manufacturer thinks you should start being concerned. And I read they changed it not to automatically accept the measured value, IIRC after the crash that involved frozen AoA vanes. Though I suppose you know this.

so after having done some more research this is what I have found.The A320 has two independent gross weight calculations. When the aircraft is on the ground the FMS does the GW calculation. Prior to engine start, the current GW and CG are not defined.; predictions are computed based on the pilot entered ZFW , ZFWCG, blockfuel and the FM calculates the TOW. The GW is calculated  by adding FOB to the pilot entered ZFW (GW=ZFW+FOB)  However I don't know what this iteration rate would be.
When the A320 is airborne, the FACs independently determine the aircraft gross weight (GW) by using the aircraft angle of attack sensors. If a significant difference occurs between the FAC and FMS gross weighs (delta > 7 tons) , the  message "CHECK GW" will be displayed on the scratchpad.

You should have edited the original answer instead of creating a new one. Does not matter too much, just for the next time.

… anyway, this is basically what we knew. The question is how trustworthy the later value is (the former is obviously as trustworthy as the load sheet).

On the A320 NEO, the internal gross weight computation is done by the FAC based on the FMS-inserted data and not anymore based on aerodynamic data. Source: Airbus FCOM.

You could work out how accurate the answer is based on the fact that the normal accuracy for Vls is +/- 3kts. Following is quoted from the manual:
The principle of the speed computation is as follows:

First, the FAC computes VS1G (stall speed). From VS1G it computes the Gross Weight (GW) which is also sent to the Elevator Aileron computers:

When the aircraft is below 14 500 ft and 250 kt, it computes this from current angle of attack, speed/Mach, altitude, thrust, and CG.
When the aircraft is above 14 500 ft or 250 kt, it computes this out of the GW, which it has memorized and updated with a fuel consumption model set in the FAC.

Finally the FAC computes the various minimum and maneuvering speeds, Vα prot and Vsw.
The accuracies of the various minimum and maximum speeds are functions of the accuracy with which the FAC computes aircraft gross weight. Normal accuracy for VLS in CONFIG FULL is about ± 3 kt.

This is old FMS. GWFK is AOA/FAC calculated, and used for Vls when landing. The GW in the lower ECAM is based on the figures you put in the FMS (fuel+ZFW). I believe the newer FMS gets Vls based on the weights you insert, and not the FAC calculated values. Also in the new FMS there is only GW and no GWFK.

the following information only concerns the A320.
The Flight Augumentation (FAC) performs the following functions:

Yaw damper
Rudder travel limiting
Monitoring of the flight envelope and computation of maneuvering speed
Yaw autopilot order
Bite fuction of the AFS

However to my knowledge, the Flight augmentation Computers, (FACs) do not calculate the Gross-weight. In fact it's the single or dual channel weight and balance system utilizing six weight sensing elements attached to mounting surfaces in the main and nose landing gear. these transducers are driven by a digital computer (WBC). The WBC computes the aircraft center of gravity and the gross weight which is communicated to the flight crew via the Display Management Computers (DMCs) the ECAM.

While I am not sure whether it is FAC that does this, I am sure the A320 calculates the weight after take-off from calibrated speed, angle of attack and vertical acceleration. It is that calculation this question is about. I was not aware of any system using sensors on gear; could this be a new feature of the later series?

This kind of information is not easy to find. Most of the engineering documentation is very abstract. Therefore I will need to study it and get back to you.

so after having done some more research this is what I have found.The A320 has two independed gross weight calculations.
When the A320 is airb

The answers are editable here. If you found more information, rewrite the answer. Also, please, add some references or at least cite the sources. Especially if the information is difficult to find, it would help others to know where to look.

Absolutely, I'll add the references for those that are interested.


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How did ICAO SARPS come to include the 250 knots speed limit for aircraft below 10,000 feet?
In certain airspace classes, a speed limit of 250 knots IAS is imposed for aircraft flying below FL100/10.000FT, according to the airspace classes defined by ICAO. How did this limit find its way into the ICAO SARPS?
The answer to this question gives a good reason why such speed limits were introduced in the USA by the FAA. I am interested in finding out why the same speed limits were de facto rolled out world wide by being included in the ICAO SARPS. Did the ICAO include the 250 KIAS below FL100 restriction for the same reason the FAA did, or are there other (additional) reasons?
For example, was this done to give pilots a better chance of spotting other traffic? To reduce the severity of bird strikes? To provide consistency with FAA rules? To allow more efficient air traffic management? To reduce noise? Or for other reasons entirely?
I am looking for actual sources on this matter, not guesses and opinions.

That seems to provide two main advantages in a busy area at a moment pilots have a heavy workload: All aircraft have limited speed differences in the horizontal plane (easier ATC separation), and vertical rate is reduced (more time for ATC and crews to react). This may be related to the higher number of slower VFR flights. Just a guess.

Part of it could simply be that most of the slower planes out there (GA, single engine, prop planes) can't fly much higher than 10,000 (without supplemental oxygen at least).  So above 10k jets don't need to worry about planes that fly almost 500knots slower, but below 10k, there's a chance there are much slower aircraft you may be flying with.

I'm curious to know why you asked the question.

The reasons for this restriction are the same- to give better chance of spotting traffic, reducing noise, preventing bird-strikes from compromising the structural integrity of the aircraft, consistency, etc. A Canadian govt. consultative document has some details (I'm unable to find the original though):

The 250 KIAS maximum airspeed below 10,000 feet MSL was a rule of flight that was introduced a number of years ago to address the bird strike hazard of modern high-speed aircraft.
Air Traffic Control adopted this maximum airspeed below 10,000 feet MSL as an air traffic management tool ...
It is also noted that ICAO rules are identical to the FARs

The primary reason appears to be safety, from the view of bird strikes and also in spotting the aircraft. Another aspect is the use of Airborne Collision Avoidance System (ACAS). From the ICAO Airborne Collision Avoidance System (ACAS) Manual:

The  surveillance range of ACAS has been designed to ensure that  sufficient warning time can be provided for collision avoidance even in  environments with heavy electromagnetic activity. This assumes that each aircraft does not have an excessive True Air Speed (TAS). Below FL 100 ACAS warning times will only be  guaranteed when both aircraft have TAS less than 250 kts.


text:
Why don't we have video recording of runways takeoffs/landings?
When planes crash at airports, it seems the only video available is amateur footage several miles away with terrible quality.
Why don't we have video recordings of all takeoffs and landings at the airport?

The flight recorders hold all the data the investigators need.
so they can just recreate the events on PC simulation and so on

Rick, welcome to Aviation.SE. Are you talking about video recording from within the cabin or cockpit or are you inquiring about external footage at airports, e.g. CCTV recordings?

This is an interesting idea... I imagine you could cover all runways and taxiways with perhaps a few hundred thousand dollars of camera in the tower, and I know the NTSB has, in some cases, used security camera footage from the airport.

A more important question than "why don't we?" is "why should we?", i.e. what benefit would we get from spending billions of dollars (worldwide) on recording millions of take-offs and landings per year? Accidents are extremely rare already; would we learn anything that we can't already find out some other way? Is the benefit - if any - worth the investment?

@Pondlife won't someone think of the news channels? plots are boring, people wants to see explosions on tv.

@Federico - you were sarcastic, agreed ! ;) However, on a more serious tone : would the news channels... pay the camera installation ? finance the maintainance ? handle the cost of monitoring ? the insurance ? etc. Worldwide ? Of course no. Anyway, we already have powerfull computers to put things in motion pictures with lots of explosions and kaboooms and torn burned metal.

Here's the thing for me. Let's say, worldwide, some great benefactor spends 2 billion USD to set this all up so that every runway, taxiway, and essentially every part of every major airport is covered with video... Murphy's Law says the next three airline accidents will occur within a mile of airports.

Billions of dollars.  U can go online and watch an Eagles nest... A swimming pool at a resort... Someone buying a cigarette at a convienance store 24/7.... Officials can observe almost every prisoner in the USA... Cost prohibitive... I don't think so. If video would not be useful then why do investigators always want to talk to eyewitnesses.???

Yes... Thanks Sentry!

A better system would be a camera tracking a flight until it was well onto climb and onto taxi on arrival.  That would however require perhaps several units, a telescope, at least a FLIR and regular spectrum camera.  Now that would probably be a nice to have in the event of an incident or violation of a regulation.
Just not sure how much data would be captured beyond the rare event of an incident, that could put some ongoing value delivery.

My first thought reading the question: how can you video-record a takeoff/landing when there is fog and almost zero horizontal visibility?

@ManuH with almost zero horizontal visibility you will not have takeoff/landing.

@vasin1987 ILS cat IIIc allow landing with almost no visibility

@ManuH agree. However no Cat IIIc is in operation as of july 2016.

@ManuH: You mean literally no visibility.  Almost no visibility is class IIIb.

Because video is mostly useless for investigation.
The investigators need to know the exact flightpath, which is already recorded by the ATC radar and by the flight data recorder, they need to know whether and which systems failed, which is recorded by the flight data recorder, and they need to know what the pilots were doing, for which they have cockpit voice recorder and the radio communication is also recorded in the ATC facility (tower).
Video would be worse for determining the flight path than both ATC radar and FDR and while ATC radar does not have attitude, FDR does and again more precisely than video. Plus video might, depending on angle, have external damage, but that can generally be determined by examining the wreckage quite fine.
So video would add very little information over the existing recordings and thus it is not cost-effective to add it for just this purpose at all airports (it may be used if it is installed for security purposes).

Actually, there have been several instances where video footage proved to be a huge asset in determining the causal factors of crashes. Off the top of my head, the 747 crash at Bagram.

@RhinoDriver: Not really. The video allowed to take an educated guess at the cause earlier on, but to make any definite conclusion the FDR data were needed and used.

And if the FDR data correlates with what the investigators see in the video then their conclusion is strengthened.  The NTSB actively seeks out video evidence, therefore Occam's Razor would lead me to believe they actually use it in their investigations.  Not only that, but the NTSB has requested cockpit video recorders several times since 2000-- they seem to be very interested in video evidence.  More so, however, unless you are an investigator yourself, or have a credible source you can cite, then that is just your opinion, and the use of video in previous cases suggests otherwise.

@RhinoDriver: Good investigator will always collect all evidence they can get, even if it is duplicate. But I haven't heard of accident where a video would be critical piece of evidence, i.e. some conclusions had no other supporting evidence except the video. No, I am not investigator, but all the reports are public. You can try to find one. As for cockpit video recorders, that is another thing; that is to record pilot actions. Even not all controls elements are recorded in FDR (e.g. circuit breaker positions) and other actions may be important (e.g. fight in cockpit).

As an airport manager, I often don't have the money to place cameras everywhere. Videos at the airport are an airport sponsor's responsibility, and most airport operators have very limited budgets. When you get into the larger airports, the cost is still an issue because of the amount of acreage that has to be covered. The other issue, is that Part 139 prohibits certain items  from being in the runway safety area, and a camera is not generally considered frangible. Even if I could put a camera by the runway, the best that I could do is a wildlife camera with at most a 70' visual distance with a heavily pixelated image.

Oh, right, like FDRs and CVRs will explain taxiway collisions. No, cameras are too expensive. Let's save then for places with deep pockets like 7-11 stores or almost every fricking place on earth EXCEPT airports.
They have something to hide. I have no idea what but somebody doesn't want them. - http://aviation.stackexchange.com/users/12563/greg-of-swallowbrook

Something to hide? Be realistic. Cameras, that can last outside in harsh conditions with minimal maintenance, that can record at high enough resolution to be useful in an investigation, that won't themselves be a danger to aircraft, that cover all the relevant areas, that can work at night or in the rain or fog or snow, not to mention all the infrastructure that goes with them (recording equipment, connections between the cameras and recorders, power) gets pretty expensive. The real question is whether all that money could be more effective on other aviation safety improvements instead.